Seat belt installation has been mandatory for a number of years via EU legislation (though each country had their own timetable I believe all do now require new vehicles to be fitted with seat belts).
Seat belt use is mandatory on coaches (all passenger carrying vehicles), and no exception would allow for permanently lying down... the only coach exception is if temporarily out of seat.
Air bags are not mandatory other than in the cabin.
Seat belt installation has been mandatory for a number of years via EU legislation (though each country had their own timetable I believe all do now require new vehicles to be fitted with seat belts).
Seat belt use is mandatory on coaches (all passenger carrying vehicles), and no exception would allow for permanently lying down... the only coach exception is if temporarily out of seat.
Air bags are not mandatory other than in the cabin.
Required fitting directive (member states applied it in 2006): http://eur-lex.europa.eu/legal-content/EN/TXT/?uri=LEGISSUM:...
Mandatory use: https://ec.europa.eu/transport/road_safety/topics/vehicles/s...